Bathroom tiles: grip, wall tiles and waterproofing

Bathroom floor tiles and wall tiles are not the same

Bath tiles split into floor tiles and wall tiles. Marazzi’s bathroom tile guide points out that floors, walls, basin areas and showers have different needs. Its first rule for the floor: use only products the maker states are suitable for floors, and check the surface most carefully where water lands.

Wall tiles can be thinner. Marazzi’s wall collections include tiles of reduced thickness, made to be fixed on a vertical surface, not walked on. A wall tile laid on a floor may look the same on day one; the label tells you whether it was made for that.

Grip on a bathroom or toilet floor

Toilet tiles and shower floors get wet every day. Slip resistance is graded R9 to R13 for shoes and A to C for bare feet in ramp tests, and the Villeroy & Boch slip-resistance sheet lists the classes German workplace rules set for washrooms:

Grip on a bathroom or toilet floor

Room	Class
Toilets	R9
Changing rooms and washrooms	R10
Hospital sanitary rooms and ward bathrooms	R10
Barefoot sanitary areas, mainly dry	A (12°–18°)
Showers and shower areas	B (over 18°, to 24°)

Pool surrounds fall under class B as well; grip outside the house is covered on the outdoor tiles page.

For toilet floor tiles at home, the same sheet is clear that no rules exist for private bathrooms, kitchens or hotel guest bathrooms. The table is still a published reference for the grip a wet room needs.

Shower floors

A walk-in shower without a tray is the wettest tiled floor in the house. For floor-flush showers, Villeroy & Boch recommends tiles that carry a barefoot class, not just an R value. Good tiles for bathroom showers therefore show both on the label, for example R10 and B.

Joint count helps too. The same sheet notes that small tiles improve grip because of the large share of grout joints. Marazzi suggests small sizes and mosaic for details in the shower area, while a large slab elsewhere in the room keeps grout lines to a minimum.

Bathroom wall tiles

Bathroom wall tiles and washroom wall tiles have no slip class to meet, so the choice is about size, finish and cleaning. Marazzi notes that gloss tiles reflect more light, while matt ones look softer and show texture. Large wall slabs mean fewer grout lines to clean; mosaic and small formats mark out niches or a feature wall.

Toilet wall tiles behind a basin or a wall-hung WC take splashes but no foot traffic, so the floor classes above do not apply to them.

Size, finish and wear for a home bathroom

For modern bathroom tiles in large formats, Marazzi advises planning slab size around the position of the sanitaryware, pipes and the cuts needed. For a 5 m² floor, the 1200 × 600 mm format means 7 tiles before cuts (our calculation: 5 ÷ 0.72 = 6.9).

A home bathroom asks little of a tile in wear. The Villeroy & Boch wear sheet places private bathrooms in wear group 1, the lightest floor class, and hotel bathrooms in group 3. Simple bathroom tiles of any floor grade meet group 1.

Waterproofing under bathroom tiles

In wet zones such as a shower area, the waterproof coating goes on the screed and walls first and the tiles are fixed over it. The data sheet of K11 Polymer Cement Waterproof Coating, in stock in Zanzibar, lists toilets and bathrooms among its uses and states that tiles can be laid on it. It gives about 1.5 kg/m² per millimetre of film in 2 to 3 coats; one 18 kg bucket covers about 12 m² at 1 mm by our calculation. More on the layers under a wet-room floor: bathroom waterproofing.

The floor tile Kitovu has in stock is the Beige Porcelain Tile 1200 × 600 mm, Matt Anti-Slip R10, with a granular matt surface. A barefoot class is not given for it, so it is not confirmed for shower floors.